Add Helidon-Reactive Scrabble benchmark (#1482)

* Add Helidon-Reactive Scrabble benchmark

* No need for pom changes

common/reactive/src/test/java/io/helidon/common/reactive/jmh/ShakespearePlaysScrabble.java

@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2020 Oracle and/or its affiliates. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.helidon.common.reactive.jmh;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.openjdk.jmh.annotations.*;
+
+/**
+ * Original copyright Jose Paumard, 2019.
+ * https://github.com/JosePaumard/jdk8-stream-rx-comparison-reloaded
+ */
+@State(Scope.Benchmark)
+public class ShakespearePlaysScrabble {
+
+    public static final int[] letterScores = {
+    // a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p,  q, r, s, t, u, v, w, x, y,  z
+       1, 3, 3, 2, 1, 4, 2, 4, 1, 8, 5, 1, 3, 1, 1, 3, 10, 1, 1, 1, 1, 4, 4, 8, 4, 10} ;
+
+    public static final int[] scrabbleAvailableLetters = {
+     // a, b, c, d,  e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z
+        9, 2, 2, 1, 12, 2, 3, 2, 9, 1, 1, 4, 2, 6, 8, 2, 1, 6, 4, 6, 4, 2, 2, 1, 2, 1} ;
+
+    static class MutableLong {
+        long value;
+        long get() {
+            return value;
+        }
+
+        MutableLong set(long l) {
+            value = l;
+            return this;
+        }
+
+        MutableLong incAndSet() {
+            value++;
+            return this;
+        }
+
+        MutableLong add(MutableLong other) {
+            value += other.value;
+            return this;
+        }
+    }
+
+    public Set<String> scrabbleWords;
+    public Set<String> shakespeareWords;
+
+    @Setup
+    public void init() {
+        scrabbleWords = readScrabbleWords() ;
+        shakespeareWords = readShakespeareWords() ;
+    }
+
+
+    public static Set<String> readScrabbleWords() {
+        Set<String> scrabbleWords = new HashSet<>();
+
+        try (BufferedReader bin = new BufferedReader(new InputStreamReader(ShakespearePlaysScrabble.class.getResourceAsStream("/ospd.txt"), StandardCharsets.UTF_8))) {
+            String line = null;
+            while ((line = bin.readLine()) != null) {
+                scrabbleWords.add(line.toLowerCase());
+            }
+        } catch (IOException ex) {
+            ex.printStackTrace();
+        }
+
+        return scrabbleWords;
+    }
+
+    public static Set<String> readShakespeareWords() {
+        Set<String> shakespeareWords = new HashSet<>();
+
+        try (BufferedReader bin = new BufferedReader(new InputStreamReader(ShakespearePlaysScrabble.class.getResourceAsStream("/words.shakespeare.txt"), StandardCharsets.UTF_8))) {
+            String line = null;
+            while ((line = bin.readLine()) != null) {
+                shakespeareWords.add(line.toLowerCase());
+            }
+        } catch (IOException ex) {
+            ex.printStackTrace();
+        }
+
+        return shakespeareWords;
+    }
+
+}

common/reactive/src/test/java/io/helidon/common/reactive/jmh/ShakespearePlaysScrabbleWithHelidonReactiveOpt.java

@@ -0,0 +1,220 @@
+/*
+ * Copyright (c) 2020 Oracle and/or its affiliates. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.helidon.common.reactive.jmh;
+
+import java.util.*;
+import java.util.Map.Entry;
+import java.util.concurrent.TimeUnit;
+import java.util.function.Function;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+
+import io.helidon.common.mapper.Mapper;
+import io.helidon.common.reactive.Multi;
+import io.helidon.common.reactive.Single;
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+import org.openjdk.jmh.runner.options.TimeValue;
+
+/**
+ * Shakespeare plays Scrabble with Helidon Reactive.
+ * Based on the work of Jose Paumard (C) 2019
+ * https://github.com/JosePaumard/jdk8-stream-rx-comparison-reloaded
+ */
+public class ShakespearePlaysScrabbleWithHelidonReactiveOpt extends ShakespearePlaysScrabble {
+
+
+    public static void main(String[] args) throws Throwable {
+        ShakespearePlaysScrabbleWithHelidonReactiveOpt s = new ShakespearePlaysScrabbleWithHelidonReactiveOpt();
+        s.init();
+        System.out.println(s.measureThroughput());
+
+        Options opt = new OptionsBuilder()
+                .include(ShakespearePlaysScrabbleWithHelidonReactiveOpt.class.getSimpleName())
+                .forks(1)
+                .warmupIterations(5)
+                .warmupTime(TimeValue.seconds(1))
+                .measurementIterations(5)
+                .measurementTime(TimeValue.seconds(1))
+                .timeUnit(TimeUnit.MILLISECONDS)
+                .mode(Mode.SampleTime)
+                .build();
+
+        new Runner(opt).run();
+    }
+
+    static Multi<Integer> chars(String s) {
+        return Multi.range(0, s.length()).map(idx -> (int)s.charAt(idx));
+    }
+
+    static <T> T get(Single<T> source) {
+        try {
+            return source.get();
+        } catch (Throwable ex) {
+            throw new RuntimeException(ex);
+        }
+    }
+
+    @SuppressWarnings("unused")
+    @Benchmark
+    public List<Entry<Integer, List<String>>> measureThroughput() throws Exception {
+
+        //  to compute the score of a given word
+        Mapper<Integer, Integer> scoreOfALetter = letter -> letterScores[letter - 'a'];
+
+        // score of the same letters in a word
+        Mapper<Entry<Integer, MutableLong>, Integer> letterScore =
+                entry ->
+                        letterScores[entry.getKey() - 'a'] *
+                        Integer.min(
+                                (int)entry.getValue().get(),
+                                scrabbleAvailableLetters[entry.getKey() - 'a']
+                            )
+                    ;
+
+
+        Function<String, Multi<Integer>> toIntegerFlowable =
+                ShakespearePlaysScrabbleWithHelidonReactiveOpt::chars;
+
+        // Histogram of the letters in a given word
+        Function<String, Single<HashMap<Integer, MutableLong>>> histoOfLetters =
+                word -> toIntegerFlowable.apply(word)
+                            .collect(
+                                HashMap::new,
+                                (HashMap<Integer, MutableLong> map, Integer value) ->
+                                    {
+                                        MutableLong newValue = map.get(value) ;
+                                        if (newValue == null) {
+                                            newValue = new MutableLong();
+                                            map.put(value, newValue);
+                                        }
+                                        newValue.incAndSet();
+                                    }
+
+                            ) ;
+
+        // number of blanks for a given letter
+        Mapper<Entry<Integer, MutableLong>, Long> blank =
+                entry ->
+                        Long.max(
+                            0L,
+                            entry.getValue().get() -
+                            scrabbleAvailableLetters[entry.getKey() - 'a']
+                        )
+                    ;
+
+        // number of blanks for a given word
+        Function<String, Single<Long>> nBlanks =
+                word ->
+                            Multi.from(histoOfLetters.apply(word))
+                            .flatMapIterable(HashMap::entrySet)
+                            .map(blank)
+                            .collectStream(Collectors.summarizingLong(value -> value))
+                            .map(LongSummaryStatistics::getSum)
+                    ;
+
+
+        // can a word be written with 2 blanks?
+        Function<String, Single<Boolean>> checkBlanks =
+                word -> nBlanks.apply(word)
+                            .map(l -> l <= 2L) ;
+
+        // score taking blanks into account letterScore1
+        Function<String, Single<Integer>> score2 =
+                word ->
+                        Multi.from(histoOfLetters.apply(word))
+                            .flatMapIterable(
+                                    HashMap::entrySet
+                            )
+                            .map(letterScore)
+                            .collectStream(Collectors.summarizingInt(value -> value))
+                            .map(v -> (int)v.getSum())
+                            ;
+
+        // Placing the word on the board
+        // Building the streams of first and last letters
+        Function<String, Multi<Integer>> first3 =
+                word -> chars(word).limit(3) ;
+        Function<String, Multi<Integer>> last3 =
+                word -> chars(word).skip(3) ;
+
+
+        // Stream to be maxed
+        Function<String, Multi<Integer>> toBeMaxed =
+            word -> Multi.concat(first3.apply(word), last3.apply(word))
+            ;
+
+        // Bonus for double letter
+        Function<String, Single<Integer>> bonusForDoubleLetter =
+            word -> toBeMaxed.apply(word)
+                        .map(scoreOfALetter)
+                    .collectStream(Collectors.summarizingInt(value -> value))
+                    .map(v -> (int)v.getMax())
+                    ;
+
+        // score of the word put on the board
+        Function<String, Single<Integer>> score3 =
+            word ->
+                Multi.concat(
+                    Multi.from(score2.apply(word)),
+                    Multi.from(bonusForDoubleLetter.apply(word))
+                )
+                .collectStream(Collectors.summarizingInt(value -> value))
+                .map(w -> {
+                    int v = (int) w.getSum();
+                    return v * 2 + (word.length() == 7 ? 50 : 0);
+                })
+                ;
+
+        Function<Function<String, Single<Integer>>, Single<TreeMap<Integer, List<String>>>> buildHistoOnScore =
+                score -> Multi.from(shakespeareWords)
+                                .filter(scrabbleWords::contains)
+                                .filter(word -> get(checkBlanks.apply(word)))
+                                .collect(
+                                    () -> new TreeMap<Integer, List<String>>(Comparator.reverseOrder()),
+                                    (TreeMap<Integer, List<String>> map, String word) -> {
+                                        Integer key = get(score.apply(word)) ;
+                                        List<String> list = map.get(key) ;
+                                        if (list == null) {
+                                            list = new ArrayList<>() ;
+                                            map.put(key, list) ;
+                                        }
+                                        list.add(word) ;
+                                    }
+                                ) ;
+
+        // best key / value pairs
+        List<Entry<Integer, List<String>>> finalList2 =
+                    Multi.from(buildHistoOnScore.apply(score3))
+                    .flatMapIterable(
+                            TreeMap::entrySet
+                    )
+                    .limit(3)
+                    .collect(
+                            (Supplier<ArrayList<Entry<Integer, List<String>>>>) ArrayList::new,
+                            ArrayList::add
+                    )
+                    .get() ;
+
+
+//        System.out.println(finalList2);
+
+        return finalList2 ;
+    }
+}